The invention relates to an aerodynamic device arranged for mounting to a vehicle or a trailer for reducing the wind resistance of the vehicle/trailer comprising a cargo space. The aerodynamic device comprises at least one sheet material, each sheet material being arranged to be mounted to the vehicle/trailer such that each sheet material is associated with a corresponding wall portion. Each wall portion has an outer surface and an inner surface, the inner surface facing the cargo space. The wall portion extends towards the rear of the vehicle/trailer, where, in a deployed first state, each sheet material is arranged to at least partly extend beyond a rearmost position of said wall portion.
The invention also relates to a vehicle or a trailer comprising said aerodynamic device.
In recent years, there has been an increased interest in improving the aerodynamic properties of vehicles in general. A major reason for this is the increased fuel costs and improving the aerodynamic properties of vehicles may reduce the fuel consumption and thus the fuel costs. In particular, professional companies in the transport and load carrying business feel an urge to keep down the fuel costs, therefore there is a desire among producers of load carrying vehicles to provide vehicles having a low fuel consumption. Many of the load carrying vehicles have a box shape such that its load compartment or trailer is essentially box shaped. There are certain benefits of this shape, in particular it is a suitable shape for managing to load as much as possible in the load compartment. However, the rear end of the load compartment will thus comprise right-angled edges, which results in that the rear end of the load compartment is not aerodynamically adapted.
In order to improve the aerodynamic properties and achieve a reduction of the wind resistance, the rear end of a trailer or load compartment has previously been modified in different ways. The use of rigid structures, e.g. air foils or the like devices, which are permanently mounted in order to improve the aerodynamic properties of a vehicle, are well known in the art. However, such structures are usually not convenient for trucks or trailers since they probably will get in the way for the doors to the loading compartment, which normally are arranged at the rear end of the load compartment. Hence, there would most probably be a need for such a structure to be easily detachable or to be mounted such that it does not interfere with the access to the load compartment through the door, e.g. by being mounted only to the doors.
However, these kinds of structures would add some length to the trailer/truck, and in many countries there are restrictions regarding the length of the vehicle such that the addition of an air foil may either make the vehicle too long or the load compartment itself smaller, i.e. shorter.
U.S. Pat. No. 4,142,755 discloses an assembly of air deflector shields surrounding the space between the tractor and the trailer, and a streamlined drag reducer shield at the rear end of the trailer whereby air drag in those regions is substantially decreased. The shields are removable to provide access to the trailer.
However, the shields have to be removed, and this is time-consumable, and requires direct handling of the large and probably dirty shields.
U.S. Pat. No. 4,818,015 discloses collapsible airfoils which reduce wind resistance for a vehicle in their operational positions, both at the front and at the rear of the vehicle. The airfoils may be moved to and from storing positions on the sides of the vehicle. Slide mechanisms for the folding of resilient airfoil sections are provided on the vehicle side walls.
However, when the rear airfoils are positioned at the storing positions on the sides at the rear of the vehicle, the vehicle width is affected, and furthermore the door opening capacity is reduced, normally the desired door opening angle is about 270°.
There is thus a desire to provide an aerodynamic device for a vehicle or a trailer, where the aerodynamic device is easily removed and re-installed without adding additional width to the vehicle, and without affecting the loading conditions i.e. not affecting the normal opening of the rear doors.
It is desirable to provide an aerodynamic device for a vehicle or a trailer, where the aerodynamic device is easily removed and reinstalled without adding additional width to the vehicle, and without affecting the loading conditions i.e. not affecting the normal opening of the rear doors.
According to an aspect of the present invention an aerodynamic device is arranged for reducing the wind resistance of the vehicle/trailer, which comprises a cargo space. The aerodynamic device comprises at least one sheet material, each sheet material being arranged to be mounted to the vehicle/trailer such that each sheet material is associated with a corresponding wall portion of the vehicle/trailer. Each wall portion has an outer surface and an inner surface, the inner surface facing the cargo space. The wall portion extends towards the rear of the vehicle/trailer, where, in a deployed first state, each sheet material is arranged to at least partly extend beyond a rearmost position of said wall portion.
In a stored second state, each sheet material is arranged to be inserted such that is faces towards the inner surface.
According to an example, the aerodynamic device comprises a first sheet material and a second sheet material. Each sheet material is arranged to be mounted to the vehicle/trailer such that the first sheet material is associated with a first wall portion of the vehicle and the second sheet material is associated with a second wall portion of the vehicle. The wall portions are mutually parallel, where the outer surfaces face away from each other and the inner surfaces face towards each other.
According to another example, the first sheet material comprises an outer edge, an inner edge, an upper edge and a lower edge. Furthermore, the second sheet material comprises an outer edge, an inner edge, an upper edge and a lower edge. The edges constitute borders of said sheet materials, where, in the deployed first state, the outer edges are closer to each other than the inner edges.
According to another example, the aerodynamic device comprises an upper sheet material which is arranged to be mounted to the vehicle/trailer such that it is associated with an upper wall portion which constitutes a roof.
According to another example, each sheet material comprises a first sub-sheet and a second sub-sheet. The first sub-sheet sheet is closer to the corresponding wall portion than the second sub-sheet, and the first sub-sheet and the second sub-sheet are connected to each other at the outer edge. The first sub-sheet is arranged to travel a longer distance than the second sub-sheet when said sheet material is moved from the stored second state to the deployed first state.
According, to another example, the sheet materials follow a curved shape in the deployed first state, constituting a mainly continuous extension of the corresponding tint wall portion, second wall portion and upper wall portion.
According to another example, each sheet material is arranged to be inserted between the corresponding wall portion and a corresponding inner wall portion.
A number of advantages are provided by means of the present invention. For example, a versatile aerodynamic device for a vehicle or a trailer, which is storable in such a way that the outer dimensions of the vehicle/trailer, and its normal workings such as cargo room door opening angles, are not affected.